1 Project Summary/Abstract 2 Attentional difficulties have been reported in deaf children and some suggest that audition is critical for the de- 3 velopment of cognitive processes such as attention. However, studies reporting attentional deficits in deaf chil- 4 dren included those born to hearing parents who were not native sign language users. Recent studies with deaf 5 native signers suggest that early sign-language acquisition is critical for the development of certain attentional 6 processes such as sustained attention and that poorer performance was observed only in deaf children under 7 age 10 during a selective attention task. Little is known about how compensatory plastic changes as a result of 8 deafness affect the ability of deaf children to covertly orient their attention in anticipation of visual stimuli. In 9 hearing adults and in some children, alpha-band (8-14 Hz) oscillatory EEG activity has been observed in the 10 posterior brain in a retinotopic pattern during the cue-target interval of a visuospatial cueing task, suggesting that 11 alpha-gating represents the endogenous suppression of irrelevant visuospatial hemifield while covertly orienting 12 attention to the cued hemifield. I hypothesize that alpha-band oscillatory EEG activity during a visuospatial 13 cueing task will be increased in deaf native signers compared to deaf late signers and hearing non- 14 signers and that lateralization will not be observed in children under 10, irrespective of hearing and 15 language status. In Aim 1, alpha-band oscillatory EEG activity will be measured in deaf and hearing adults and 16 children aged 6-13. Deaf subjects will either be native signers or late signers (defined as those who acquired 17 sign language after the age of 5), and hearing subjects will have no exposure to sign language. Additionally, the 18 microstructural properties of the white matter tracts involved in attentional processing have not been studied in 19 deaf children. Diffusion tensor imaging allows for the measurement of fractional anisotropy (FA), which is a 20 measure of white matter connectivity. I hypothesize that FA will be decreased in the dorsal attention net- 21 work of deaf children exhibiting reduced alpha-band oscillatory EEG activity. In Aim 2, DTI will be per- 22 formed to measure FA in regions-of-interest (ROIs) involved in visuospatial processing for deaf native signers, 23 deaf late signers, and hearing non-signers aged 6-13. The overarching goal of this project is to test the hypoth- 24 esis that reported attentional deficits in deaf children are due to a combination of auditory deprivation and delayed 25 sign-language acquisition. Understanding the effects of auditory deprivation and delayed sign-language acqui- 26 sition on attention is critical for the development of interventional strategies after the initial diagnosis of deafness. 27 In addition to mastering techniques required to complete this project, the opportunities for professional develop- 28 ment and clinical training as described in my training plan will prepare me for a career as a physician-scientist in 29 the field of cognitive neuroscience.